P1569: COVID19 AND ITS IMPACT ON HEMATO-ONCOLOGICAL PATIENTS. DIFFERENCES IN OUTCOMES IN RELATION TO OMICRON CIRCULATION AND VACCINATION STATUS?
Authors: A. Addiego, A. I. Prado, V. Moraes, P. Cano, I. Gervaz, L. Perez, R. De Giuda, A. Flores, E. Riva, M. Ferrando, S. Grille, G. Borelli, A. Vazquez, M. Stevenazzi, R. Gabus, A. I. Landoni, C. Guillermo, M. Boada
Journal: HemaSphere (2022)

Background: COVID-19 has a pleomorphic presentation that goes from asymptomatic patients to critical disease with pneumonitis as the lead complication. Main risk factors for critical illness comprise age, cardiovascular disease and obesity. In Hemato-oncological patients, immune response is impaired due in part to their disease and also oncological treatment. Lethality rates reported for these patients are higher than general population and there is a trend towards a greater impact in patients diagnosed in the last 5 years. Our country has experienced two COVID-19 waves since the first cases in march 2020. There is national evidence of less Iethality and critical cases with omicron circulation Aims: To present an interinstitutional registry of COVID-19 patients with underlying hemato-oncological diseases. Methods: We included patients with hemato-oncological diseases assisted at Hospital de Clínicas and Hospital Maciel from Montevideo Uruguay, who were diagnosed with COVID-19 between march 2020 to February 2022. Risk factor presence was established as one of the following: age older than 60, cardiovascular disease and obesity. Full vaccination was defined as two doses and 14 days after last injection. Omicron circulation refers to the period between December 2021 and February 2022 when Omicron variant was responsible for more than 99% of cases in Uruguay. Results: 110 patients were included with a median age of 53 years. Diagnosis comprises 51.8% (n=57) chronic lymphoprolipherative diseases, 20% (n=22) monoclonal gammapaty, 14.5% (n=16) chronic myeloprolpherative diseases, and 13.6% (n=15) acute leukemias and myelodysplastic syndromes. A 34.5 % of the patients were fully vaccinated. Hospital admission was required in 23.6% and there was 14.5% of critical cases. Global lethality rate was 14.5% (n=16), higher than global lethality reported for Uruguay in the same period (0.84%, with a total of 815704 infections). Figure 1 shows data adjusted by disease, illness status, hospital admission, risk factors, vaccination status, and omicron circulation. Requirement of hospital admission, and presence of risk factors were associated with higher lethality (p=0.0001. and p=0.0022), whereas active disease was associated with more lethality but with no statistical difference (p=0.058). Lethality was inferior in full vaccinate state (5.3% vs.19.4%), but with no statistical difference (p=0.0504). Our data reveals a trend towards inferior lethality during omicron wave (9% vs 18%), however not statistical difference was shown. Image:Summary/Conclusion: We present an interinstitutional registry from the main hematologic public centers in Uruguay. Patients included present a broad spectrum of hemato-oncological diseases. The proportion of vaccinated patients is significantly inferior to general population in our country (34.5% vs. 77.1%). Admission requirement and presence of risk factors were associated with higher lethality. Although full vaccination and omicron circulation seem to be associated with inferior lethality, difference was not statistically significant. That may be in relation to the number of patients included and ought to be evaluated prospectively. COVID-19 outcomes in hemato-oncological patients are substantially inferior to general population and our data suggest that impact is greater in patients with active disease. We believe that hemato-oncological patients constitute a vulnerable population in regards to COVID-19 justifying solid directed actions such as booster vaccination.